Apparatus for annealing glassware



April 8, 1930. T. WARDLEY ET AL APPARATUS FOR ANNEALING GLASSWARE FiledJune 21, 1928 s Hm n m r h S I my h m @7 M L o no. H x ,m w m N m- H m QS & Afi E J. v m M. x m MN E G m m /3 0d Patented Apr. 8, 1930 UNITEDSTATES PATENT OFFICE THOMAS WARDLEY, OF GREEN FORD, AND HAROLD V. E. M.RENN, OF WEST EALING,

ENGLAND, ASSIGNORS TO HARTFORD-EMPIRE COMPANY, OF HARTFORD, CONNECT-ICUT, A CORPORATION OF DELAWARE APPARATUS FOR ANNEALING GLASSWABEApplication filed June 21, 1928, Serial No. 287,201, and in GreatBritain .Tune. 29, 1927.

5 flue or flues or the like adjacent to or in close proximity'to achamber, tunnel, or the like, through which are passed the articles orware to be annealed. The invention has more particular, though notexclusive, reference to lehrs in which the articles are carried throughthe chamber, tunnel, or the like, on an endless conveyor constituted bya flexible band of heat resistant material, such as flexible openwork ormesh fabric, that travels in contact with or in close proximity to asmooth surface of a plate or the like that may form the upper part ofthe flue through which the hot gases or products of combustion pass,preferably at sub-atmospheric pressure. The articles in passing throughthe lehr are first subjected to a uniform or approximately uniformtemperature for a predetermined period during which they are allowed togain temperature uniformity prior to the commencement of the coolingprocedure for which latter there is a gradual and slight decrease in thetemperature until a certain stage is reached, thereupon the rate oftemperature drop is greatly increased to effect rapid cooling of thearticles .01 ware.

An object of the present invention is to enable an increase in thetemperature of the lehr tunnel to be brought about when required withoutnecessarily increasing the amount of heat initially applied to the lehr.It is well known that the greater the speed of hot gases flowing alongthe flue consequent, for example, upon a smaller cross section of theflue, the higher will be the temperature on the side heated by the aswith a resulting increase in the amount of heat transmitted. We applythis principle to lehrs and our invention consists in so designing theflue or passage for the hot gases or other temperature controllingmedium that a greaterrate of heat transference from the flue to thetunnel or chamber containing the articles or Ware can be effected at anydesired section or sections of the lehr.

According to this invention, the flue or paseffected at the initial orgradual cooling stage,

so that temperature conditions can be varied according to requirements.For instance, when the weight of the ware being annealed per unit oftime is comparatively small, it may be'desirable to raise thetemperature at the lower end of the critical annealing stage to thetemperature obtained in the corresponding zone when the weight of theware being annealed per unit of time is substantially greater. This isaccomplished by gradually reducing the cross sectional area of the flueat the required position without varying the surface area of the partthrough which heat is transferred to the interior of the tunnel, so thatthe velocity of the hot gases passing through the restricted portion ofthe flue is increased, with the result that there is an increased heattransference between the gases and the interior of the tunnel. Means maybe provided whereby the said increase in the heat transference may becontrolled, so that the temperature environment in the lehr tunnel canbe regulated accordin to requirement. For example, the transmission ofheat may be decreased at the section where provision is made for theincreased heat transference by the admission of cold air, to bring aboutthe required reduced temperature environment in the lehr, or this may beeffected by adjustable means which permits of variations in the crosssectional area, for example, by the use of an adjustable elongateddamper, vanes or the like in aflue which is normally of constant oruniform cross sectional area.

We have chosen to illustrate our invention in connection with a lehr ofthe general type shown by the patents to Mulholland Numbers 1,560,481,granted Nov. 3, 1925 and 1,571,137, granted Jan. 26, 1926, each of whichshows a lehr having an elongate tunnel, means for conveying articles ofglassware therethrough, a heating flue or flues beneath the tunnel andextending longitudinally thereof with suitable controls at spacedintervals therealong and a cooling flue or flues extendinglongitudinally above the tunnel from the cooler or exit end materialportion of the length of the tunnel and having suitable controls atspaced intervals thereon for controlling the cooling action.

Our present invention contemplates a method of annealing glassware inwhich the ware in the tunnel is carried through zones of progressivelychanging temperature and in which the temperature gradient alongsubstantially the entire length of the lehr may be controlled at will.The present invention includes, in addition to the control shown anddescribed in connection with the Mulholland patents, the idea of varyingthe temperature gradient in the tunnel by varying the rate of heattransfer between the ware therein and the gases in a temperaturecontrolling flue by varying the velocity of such gases in apredetermined zone or zones.

In order that the said invention may be clearly understood and readilycarried into eifect, the same Will now be described more fully withreference to the accompanying drawings in which;

Figure 1 is a vertical section of a lehr embodying the presentinvention;

Figs. 2 and 3 are transverse sections on= the lines II, II and III, IIIin Fig. 1 respectively; and

Fig. 4 isa fragmentary longitudinal sectional detail view showing analternative arrangement.

.Referring to Figs. 1, 2 and 3, the lehr is formed with a flue 2 havinga permanent gradual decrease in cross sectional area formed by a bottomplate or wall 3 which is inclined upwardly in the direction of flow ofthe hot gases from a fire box 4. The surface area of the upper part 5 ofthe flue through which the heat is transmitted to the interior 6 of thelehr tunnel, in which are positioned the ware or articles to beannealed, is shown as uniform throughout the length of the flue and isnot reduced in reducing the cross sectional area of the flue itself asindicated in the sectional views, Figs. 2 and 3.

In order that there may be a gradual return to the normal or'full crosssectional area of the flue from the position where the area is reduced,an additional plate or wall 7 is provided which is inclined in theopposite direction to that of the plate 3. The length of the additionalplate 7 measured in a direction longitudinally of the flue is less thanthat of the plate 3, but the ratio of their respective lengths may be asdesired, dependent upon the required temperature conditions wlthin theinterior 6 of the lehr. Control or variation of the temperatureconditions in the lehr during its operation is efl'ected by theprovision of a plurality of dampers or controllable inlets 8, wherebycold air from the outer atmosphere may be admitted to the flue to dilutethe hot gases passing therethrough when, for example, the increase inthe heat transference is not required or when less heat is required,as'for instance when annealing a greater weight of ware per unit oftime. The dampers or controllable inlets 8 may be similar to those usedfor the admission of coolin air in lehrs of the kindhereinbefore referreto and shown in the Mulholland patents and they are arranged atpositions along or adjacent to the inclined plates 3 and 7 at the bottomof the flue.

Alternatively, the lehr may be constructed with a flue which is ofconstant or uniform cross sectional area and which is provided with anadjustable plate or elongated damper 9 which may normally lie parallelto or flush with the bottom of the flue (Fig. 4) The plate 9 is adaptedto be adjusted by means of a hand wheel control 10 or similar device,whereby its inner end at a: may be moved towards the upper plate 5 ofthe flue so that it assumes an inclined position similar to that of theplate 3 in Fig. 1 and thus provides a gradually reduced or restrictedpassage for the hot gases when it is desired to increase the heattransference for raising the temperature in the interior 6 of the lehr.A further plate 11 is provided which is adapted to be moved togetherwith the plate 9 so that the cross sectional area of the flue, beyondthe restricted portion, may gradually assume its normal or full crosssection.

While we have shown the invention applied only to the heating portion ofthe lower iue 2, it is obvious that the same or similar mechanism couldequally well be used in connection with the right hand or cooling end 12of the flue 2 (Fig. 1) which is used as a cooling flue and in whichcontrollable amounts of air are inducted through the dampered passage 13and drawn off through the inclined passage 14 to the header 15 andthence through passages on either side of the lehr tunnel to the upperwind box 16 from which they are drawn by any suitable means such as anexhaust fan. We have shown a. longitudinal upper cooling flue 17extending from the exit end of the lehr and open at said end, as at 18,and provided with a plurality of dampered openings 19 communicating witha take-off conduit 20, which in turn communicates with the wind box 16.Thus it will be seen that suitable means are provided for cooling amaterial portion of the lehr tunnel, this means being controllable inits effeet by a suitable adjustment of the dampers in passages 19. Theflue 17 may be constricted by means such as are shown in Figs. 1 and 4and this construction is contemplated by us.

The elongated members or dampers 9 and 11 may also be made as a longflexible strip adjustable at intervals along its length by any suitablemeans, such as are shown at 10, for varying the cross section of theflue progressively from one point to another as may be desired.

While we have shown and described but two specific embodiments of ourinvention, many modifications may be made therein without departing fromthe spirit thereof, as set forth in the appended claims, which are to beconstrued as broadly as the state of the prior art permits.

We claim:

1. A lehr for annealing glassware comprising a tunnel, a flue associatedwith said tunnel,"and means for passing a temperature controlling mediumthrough said flue, said flue being of varying cross sectional area andhaving the surface area through which heat is transferred between theglassware and said temperature controlling medium in said flue uniformthroughout the lengthof said flue.

2. A lehr for annealing glassware comprising atunnel, a flue associatedwith said tunnel, means for passing a temperature controlling mediumthrough said flue, and means for Varying the cross sectional area ofsaid flue along a portion 'of its length including an inclined plateconstituting a portion of one wall of said flue.

3. A lehr for annealing glassware compris ing a tunnel, a flueassociated with said tunnel, means for passing a temperature controllingmedium through said flue, and adjustable means for varying the crosssectional area of a portion of said flue.

4. A lehr for annealing glassware comprising a tunnel, a flue associatedwith said tunnelymeans for passing a temperature controlling mediumthrough said flue, and means. for adjustably varying the cross sectionalarea of a portion of said flue mcluding an elongate inclined damperpositioned within said flue. v

5. A lehr for annealing glassware comprising a tunnel, a flue associatedwith said tun.- nel, means for passing a temperature controlling mediumthrough said flue, and means for adjustably varying the cross sectionalarea of a portion of said flue including an elongate damper disposedwithin said flue and parallel with the outer wall thereof when 1nposition to give said flue 1ts greatest eifective cross/sectional area.I

6. A lehr for annealing glassware comprising a tunnel, a longitudinallyextending flue having a common wall with said tunnel, means for passingatemfperature controlling medium th ough said ue, and means for ing atunnel, a longitudinally extending flue having a common wall with saidtunnel, means for passing a temperature controlling medium through saidflue, and means for varying the cross sectional area in apredetermined'portion of said flue while maintaining constant the wallarea thereof in heat transfer relation with the glassware in saidtunnel.

- 8. A lehr for annealing glassware comprising a tunnel, alongitudinally extending flue having a common wall with said tunnel,means for passing a temperature controlling medium through said flue,and means for adjustably varying the cross sectional area of'a portionof said flue including an elongate inclined damper positioned withinsaid flue and constituting a part of the wall thereof opposite saidcommon wall.

9. A lehr for annealing glassware comprising a tunnel, a longitudinallyextending flue having a common wall with said tunnel, means for passinga temperature controlling medium through said flue, and means forvarying the temperature gradient Within said tunnel including aprogressively constricted portion in said flue, the common wall of saidflue being of uniform width throughout the length of said flue, wherebyto vary the velocity of the medium within said flue and consequently therate of heat transfer between said medium and the walls of said flue.

10. A lehr for annealing glassware comrising a tunnel, a longitudinallyextending 'ue having a common wall with said tunnel, means for passing atemperature controlling medium through said flue, and means for varyingthe temperature gradient'within said tunnel including a progressivelyconstricted portion in said flue, said constricted portion beinginterposed between unconstricted portions along said flue.

Signed at London, England, this 11th day i of June 1928.

THOMAS WARDLEY. HAROLD V. E. RENN.

varying the cross sectional area in a predetermined portion intermediatethe ends of said flue.

85W 7. A lehr for annealing glassware compris-

